Process of making pulp



(No Model.) y

G'. L. HUXTABLE.

PROGESS 0F MAKING PULP.

No. 269,291. Patented Deo.19, 1882.

N. PETERS. PhnwLlmagnphw, wnmngw". n. cA

GEORGE L. HUXTABLE, OF LAUREL, INDIANA, ASSIGNOR OF ONE-HALF TO SIMPSON & GAULT, OF CINCINNATI, OHIO.

PROCESS oF MAKING PULP.

SPECIFICATION forming part Of Letters Patent No. 269,291, dated December 19, 1882.

Application filed March 11, 1881. Renewed November 23, 1882. (No model.)

To all whom fit may concer/n Be it known that I, GEORGE L. HUX'rABLE, a citizen of the United States, residing at Laurel, in the county of' Franklin and State ot' Indiana, have invented certain new and useful Improvements in Processes of' Making' Pulp, of which the followingis a specification. My invention relates to an improvement in the process of reducing wood and other fibrous -io articles to a pulp for paper-making.

The processes for reducing wood to pulp hitherto used were, first, by means of boiling the chips in a solution of' caustic soda or other chemicals under steam-pressure. The cost of' x5 the reduction by this process is very much more than by mine. Besides, I avoid the use of expensive machinery. Another process for reducing wood pulp by purely mechanical means is to take blocks of wood and hold them 2o against theface of coarse grindstones or emerywheels. This process is objectionable, first, because of the large amount of' power required and the slowness of the process; and, second, the pulp removed by the revolving stone is not z5 of uniform finencss, but requires regrinding, which in a great measure destroys the wood ber and produces an inferior article of pulp.

My invention consists in reducing wood or other fibrous material to pulp by first reducing` 3o the wood to small blocks by cutting or sawing, or by both cutting and sawing, until it is small enough to be fed into millstones in a manner similar to grain, except a continuous stream ot' water is introduced with the wood, which is ground by the stones, and the water carries oft' the finer or pulpy parts as fast as it is reduced and prevents itfrom beingretained long in the coarser mass, which would cut or injure the ber. The product from the first set of' 4o millstonesiscarried immediatelyinto asecond set, and the water in like manner carries off the finer portions as fast as reduced to prevent cutting or injury of' the ber, and this process of gradual reduction by regrinding it in a liner set of' mills is continued until the fiber is sufficiently reduced to form pulp.

My invention overcomes the objection eX- isting in the ordinary mechanical processes of reducing wood pulp, and produces a superior 5o wood pulp by purely gradual mechanical reduction and at a much less cost than by older processes.

Other features of' my invention will befully set forth in the annexed description of' the drawings.

In the accom pauyingdrawings, Figure 1 represents a series of" reducing-mills. Fig. 2 represents a sawing or cutting device.

A represents a series of' saws, which are set close together, mounted upon an ordinary` ar- 6o bor or mandrel, B. Thesesa Ws are preferably made of one-eighth of' an inch or upward in thickness, with the teeth t'ormed like ordinary crosscut buzz-saw, except the teeth are tiled so that the edge is slightly beveled to incline toward the logthatis,I use no set in the saw and tile the teeth all upon one side, so that they will draw toward the log in cutting. The thickness of these saws is determined bythe desired length of the fiber. 7o

B represents a log which is reduced to very coarse sawdust, somewhat resembling short splinters, ofunif'orm length,and quite free from the dust or flourof' wood. Instead of using this kind of reducing-machine for the first step of my process, a series ot' cutting-knives or a a bark or bone grinding mill maybe employed, the object being to reduce the wood to a liber, and as free from dust as possible, toa sufficient ineness, so that it can be fed into a burr or 8o grinding mill.

Fig. l of the drawings shows a series of' reducing-mills, C D E.

F G H represent common millstones, which y preferably are sandstones. These stones are dressed with furrows deeper at the eye and running out to a gradual or less depth toward the periphery, and the last or finishing set of' stones', in which the f'urrow'should terminate slightly within the peripheral line. Itis de- 9o sirable, also, to have the fui-rows nearer together than in the ordinary mills. as the grinding is done at the upper edge ofthe furrow. The more furrows the more rapid the operation. In practice I have usually used four sets of' 95 these stones, but have sometimes used but three, as when one set of' stones was being dressed the process was carried out by the remaining three sets and good results obtained.

I represents a water-pipe, which carries a roo stream of water into the eye of the grindingstone F.

K L represent spouts which are used to carry the Water and fibers from one set of millstones to the other, and they should have requisite pitch to accomplish this object.

M represents the hopper into which the fiber product prepared for grinding is fed into the stones. Care should be taken to adjust the setting of these different stones so that the last set shall not be crowded in its work. In practice the work of gradual reduction is chiefly performed before the product passes to the last set of millstones, and by having a smooth surface just at the periphery of the stones I am lenabled te reduce any coarse particles that have escaped the proper reduction in the other sets ot' stones. This feature is not essential; but I deem it the preferable way of carrying out the process. 1t is preferable to have each successive set ot' stones with the furrows shallower at the periphery than the preceding set. This is not absolutely essential; but it is essential to have the furrows decrease in depth as they approach the periphery, and where they grad nally terminate. In this respect they dift'er from ordinary grain-mills.

Itis manifest that other fibrous material than Wood may be reduced in the same manner, substantially, the different steps being somewhat varied.

The liquid pulp produced by my machine and process is prepared for use of paper or for commerce by a wet-mill in the ordinary Way.

I claiml. The herein-described process of making pulp from wood or other fibrous material by the gradual reduction ot' said fiber by successive series of rubbings between a series of grindingmills constructed and arranged substantially as herein set forth.

2. The herein-described mode or process of the gradual reduction of wood or other fibrous material, which consists, irst, in reducing the material to a coarse consistency suitable for being fed into a grinding-mill, into which it is admitted with a stream of Water to assist in rubbing, and thence carried into another set 0f millstones, where it is still further reduced, which gradual reduct-ipn by grindingmills is successively continned'until the fiber is uniformly reduced to anished pulp, substantially as herein set forth.

3. In the manufacture of pulp from Wood or other brous material, a series of instruments consisting essentially of a sawing or cutting mill, A, and a series of grinding-mills, G I) E, or their equivalents, arranged ill-consecutive order, so that the product ot' the cutting-machine can be introduced into the tirst mill in connection with a stream of Water and pass through the series of mills, by which it is gradu ally reduced to a finished pulp, substantially as herein set forth.

4. A series of reducers, C D E, each consisting of a pair ot' mill grinding-stones the furrows of which are dressed to gradually terminate at or near the periphery, and adapted to a grad ual reduction ot wood or other iibrous material to -a nished pulp by the successive operation of the series, substantially as herein set forth.

In testimony whereof I have hereunto set my hand in the presence ot' two subscribing witnesses.

GEORGE L. HUXTABLE.

Witnesses:

J. H. CHARLES SMITH, JNo. E. JONES. 

